hoof revision and disease Flashcards
define keratinisation
define cornification
Define horn
label the hoof capsule and corium
Label the hoof capsule and corium
Describe the composition of the hoof
Describe the arterial supply to the equine foot
3 zones for blood supply:
proximal dorsal - via branches from digital arteries, supplies coronary band
Distal dorsal - via palmar/plantar digital arteries
Palmar supply - via branches from palmar digital arteries to heel bulbs, part of sole and frog
Describe the venous drainage of the equine hoof
satellite veins (parallel to arterial supply)
Why is the venous drainage of an equine hoof important in laminitis?
many arterio-venous anastomoses can divert blood away from corium
this exacerbates ischeamia and tissue damage, impaired blood flow and oxygen supply to corium contributes to pain and progression of laminitis
How is horn/hoof produced?
- basement membrane and dermis form elongated dermal papillae at coronary band
- basal cells produce keratinocyes as usual, which become squames
- keratin squames glued together to form tubules
- tubules glued together by intertubular horn to form hoof/horn
- hoof slides over/between dermal lamella
- takes 12-15 months for hoof to grow from coronary band to ground
What do the perioplic and sole dermis do in hoof/horn production?
Perioplic dermis - produces a thin, waxy, waterproof cover
Sole dermis - produces sole at same rate as coronary dermis
Describe the anatomy of the coronary band/corium
Label this diagram of hoof growth
Describe the epidermal lamellae of the equine hoof
Describe the dermal lamellae of the equine hoof
What is the role of the dermis and epidermis in the hoof?
Dermis - blood, nerve supply
Epidermis - protection, hoof formation
Label the dermis and epipdermis of the claw/hoof
Describe the dermal epidermal junction and how this relates to horn growth
Horn (epidermis) slides over corium
Corium (dermis) attached to P3
These layers interdigitate
What is secondary lamellae in the equine hoof?
increases area of basement membrane, increases strength of dermal-epidermal bond
What is the function of secondary lamellae in the equine hoof?
This ensures structural integrity, distributes weight, absorved shock, stabilises coffin bone, facilitates blood flow, protects against injuries and infection
How are hemidesmosomes linked to laminitis?
hemidesmosomes break down in laminitis as the basement membrane breaks down
what are MMPs and TIMPs?
MMP = matrix metalloproteinases - enzymes that break down and remodel ECM in tissues
TIMPs - natural inhibitors that help control the excessive degradation of the ECM by MMPs
